Telephone switching key



.A. n. vHMGAN. TELEPHONE SWITCHING KEY. APPLICATION FILED ,AUG-26. |921.

1,432,852, Patented Oct. 24, 1922.

7 Fig e mum A Q 'www Patented Oct. 24, 1922.

UNITED STATES PATENT OFFICE.

AUGUSTUS D. HARGAN, OF BAYONNE, NEW JERSEY, ASSIGNOR T0 WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SWITCHING KEY.

Application filed August 26, 1921.

10 all i0 hom t may concern:

Be it known that I, AUGUSTUS D. HAR- GAN, a citizen of the United States, residing at Bayonne, in the county of Hudson, State of New Jersey, have invented certain new and useful Improvements in Telephone Switching Keys, or' which the following is a full, clear, concise, and exact description.

rlhis invention relates in general to electrical switching devices and more particularly to telephone key switches of the type generally known as ringing or recording keys.

Such keys are used in telephone systems and comprise a plurality of key units having a single mounting. They are generally provided with interlocking means to lockt euch unit in its operated position and means to release such unit upon. operation ot' another unit. The most generally adopted torm ot key unit comprises a phirality ol keys provided with an interlocking means which maintains one or more ot the keys in a circuit controlling position until released by the operation ot another key. The interlocking nieans for the keys heretofore em ployed com prised levers or plates hinged or sliding in the mounting trame.

'lhis invention relates particularly to the interlocking means employed with keys and has vfor its object to provide a simple and inexpensive construction which is positive in its action and substantially trictionless.

'l`o accomplish these objects, the interlocking mechanism is mounted on springs which also provide a means Vlfor actuating the mechanism.

One torni which the invention may assume in prat-,tice is illustrated 'in the accompanying drawing, in which Fig. l is side elevation, parts being broken away to more clearly show the constructioi'i.

yFig. 2 lis a vertical cross sectional view taken on the line 2 2 ot Fig'. l.

Fig. 3 is a vertical cross sectional view taken on the line 3--3 of Fig'. l.

leterring now to the drawings in detail, the re'lerence numeral lY indicates a frame which comprises a metal sheet bent into the form ol' a U having a long leg 2 and a short leg P. (')n the leg 2 are mounted a plurality ot switch spring' units oi which 4, 5 and (3 are typical. Through the `upper portion ol? the traine l project key plungers T, S and 9. Each oi the plungers Serial N0. 495,647.

7, 8 and t) comprises a square shank 10, a cam 1l and a rod l2. The square shank 1U of each plunger fits through corresponding aperture in the upper portion ot the .frame l allowing the plunger to be moved longitudinally parallel to the leg 2 thereot. l On the rod l2 is mounted a pair of rollers '1.3 which cooperate with the master springs ot the spring units 4 5, and 6 to produce the desired circuit change. The rod l2, toward its lower end, slides through a guide 14 which is mounted on the leg 2 ot the lrame l. A coil spring l5 is mounted on the rod 'l2 and presses against the guide Ll and makes the normal tendency in each plunger to return to its elevated or non-operated position.

The lockingmeans comprises a pair oit fiat strips it) `ioined at the ends and inserted between the legs 2 and i of the Atrame ll. Thestrips i6 lie on each side o'lA the cams il and are provided with transverse pins 1.7 each supporting a sleeve 2l, adjacent each ot the cams. The Ylraniework Yl'ormed by the strips v16 is supported by longvertical '['lat springs ,18 and i9, one end olt each spring being fastened at the end o'lt the locking 'trame and the other ond being sui'iported by leg 2 ot the trame 1.

llpon depression ol a plunger. as tor instance plunger 9, the trame forced to the left until the top ot the cani has passed beyond the sleeve 2l. Under the intluence ot the springs i8 and it), the trame then moves to the right, locking the key in its depressed position as shown in F l..

By the depression 0i any other key, such as "i" or the lockilm` trame is 'forced to the lett by another cani thus removing` the sleeve 251 as an obstruction tothe Yformerly depressed plunger 9 and the plunger returns to its nor mal position under the intluence oi" Ithe spring' l5. the depressed key being thon locked in its depressed position.

A pair ofcontact springs 2() are provided which are operatedv hy the longitudinal motion o'lf the locking Atrame i6. The master spring of the spring combination t2() bears against the spring- 'i9 and makes and breaks contact with its contact spring` as the spring' i9 moves to the rigl'it and lelt controlled by the plungers 7, S and S) as previously de scribed.

lt is obvious that the above described construction has lecidedly important advantages over key structures heretofore employed, inasmuch as the only points Where l'rietion can occur in the interlocking means are at the bearings between the cams 1l and the sleeves 2l, and these members are so formed that all possibility o't trouble resulting from fric/tional Wear or sticking is avoided.

iVbat is claimed is:

l. In Combination, a row oiI switching keys, each havingan operated position and a non-operated positini,A a locking bar, comprising a frame snrrou'ndinp,` the stems ofi said keys, said' trame being movable longitudinally olf the row of keys and earr' \y'ing transverse members for holdingA the keys in the operated position, and autoinatically releasing them from suchl position, andspring` means for siiipporting and aetuatingsaid bar.

2. ln Combination, a plurality of switching keys eael'l having; an operated position and a non-operated position, a looking` bar comprising a 'traine surigoninlinp the stems of the keys and fariyinotransverse members to hold the keys in the operated position, and to automatically release them. 'from such position andV spring means attached to said lfieliiiirr;l bar rfor siipijiorting; and actuating said bar. l

ln combination, a plurality otswitching keys each haying an operated position and a non-operated position. a looking` bar eolnprising a traine surroUllding` the stem off the keys and carrying transverse members to lock any key in its depressed position and to release a depressed key upon the depression oil any other key, and spring means at taelied to the sides ot said frame for snpporting` and actuating said `lookingbar.

4. ln Combination, a pliiirality of switching,l vkeys each having an operated and a non-operated position, a looking` bar comprising' a rectangular frame surrounding the stems ot' the keys and carrying` transverse rollers to Coopera-te with Cams on the key stems to look any key in'its depressed position and to release a depressed key upon the depression oi any other `key, a spring` member tor supporting each end' oli' said f locking bar and for actuatingl said: l'ock'i'inf; bar and a switch member directly actuated by Aone o'l" said springmembers.

5.111 combination, a row of switching; keys, each having an operated position and a non-operated position, inverted triilncated cone shaped cams upon the stems ol said keys, a looking' bar surroundin@` the stems ot said keys` said bar be. movable londitudinally olf the rouv oit llzeys and carryingl transverse rollers 'lor eooperating),I Vwith said Cams, whereby the keys are looked in the operated position and aiitomatirally re leased troni suoli position, and .springl means 'lor silpporting` and actuating said' bar.

ln witness Wliereo'l` l hereunto subseribe my name this 23rd day ot August A. D., 1921.

AUGUSTUS D. HLA lil 

